Rotella T 15w-40 is amaizing stuff. For diesel engines, or any engine without roller rockers initial startup is the big wear point, lifters on the cam wear is a killer. The europeans use an ACEA oil rating system, not all oil for sale here in the US have the rating, but for diesels you need at least a B3 rating which Rotella has, the synthetic has a B5 but is more expensive. I buy Rotella in the 5 gallon pail at Advance when they send me a save $20 on a $100 purchase coupon. You can also get it in a white gallon jug at Walmart or any truck stop for less than $12 a gallon. The Synthetic comes in a blue jug at about $19 per gallon, I use it in the Smart and Boxster.
There are several synthetics availabe at A5/B5 but Rotella is by far the cheapest.
